The check was found to be late maturing and therefore was eliminated from the analysis.
Generally the materials planted at Mtwapa took a longer time (83 days) to reach days to heading while shorter time was observed at Msambweni during the long rain season (72 days) (Table 4.4). The same trend was observed for days to anthesis and days to maturity.
The highest mean number of productive tillers per plant of 11 was observed at Msambweni and ranged from 7 to 16 productive tillers per plant. Mtwapa showed the lowest mean number of productive tillers per plant of 7 ranging from 5 to 10 productive tillers per plant.
Matuga showed the shortest average plant height of 93 cm while at Msambweni, plants were tall showing a mean plant height of 108 cm. Across environments, the earliest populations with the shortest days to heading were crosses between E x E (early x early), CT16323-CA- 25-M x Vandana (70 days) followed by NERICA 1 x Vandana (71 days). Two early maturing parents NERICA 1 and CT16323-CA-25-M dominated the early class. The early class was dominated by crosses between E x E, and E x EM (early x early to medium). In addition, the majority of the crosses were between interspecific x Oryza sativa and interspecific x interspecific. The latest maturing population was Luyin 46 x IR74371-54-1-1 with 92 days to heading. The late maturing populations were mostly crosses between M x M (medium x medium) and M x EM (medium x early medium) and the common parents were medium maturing parentsNERICA-L-25 and IR55423-01. Number of productive tillers per plant of the selected early maturing populations was low (5 to 9 tillers) while plant height was intermediate (90 to 125 cm).
4.3.3.2 Random managed drought stress
Under random managed drought stress in Msambweni, the average days to heading was 75 days (Table 4.5). Compared to the no drought stress environment on the same site during long rain season, there was a mean delay in flowering of three days and a mean delay in maturity of 5 days. The mean number of productive tillers per plant was 9 and mean plant height was 102 cm. The population Duorado x IR74371-54-1-1 showed the earliest days to heading of 66 days maturing statistically earlier than parent IR74371-54-1-1. Other populations showing shorter days to heading of less than 70 days were CT16323-CA-25-M x IR55423-01, CT16323-CA-25-M x IR74371-54-1-1, and NERICA 1 x Vandana. The early class was dominated by crosses between E x E, E x EM and E x M and vice versa. Sixty percent of the early maturing populations were between interspecific and Oryza sativa lines.
Vandana, an early maturing line, was the common parent appearing in 40% of the selected
early maturing populations. The population, Vandana x IR74371-54-1-1, combined earliness with higher number of productive tillers per plant of 11. The latest population was Luyin 46 x IR55423-01 (M x M) with 88 days to heading. Once more, the latest maturing populations were mostly crosses between M x M and M x EM and the common parent was IR55423-01 (M). Low (5 to 9 tillers) number of productive tillers per plant was observed for most of the populations. Plant height was mainly intermediate with populations CT16323-CA-25-M x Vandana (E x E) and Duorado x Vandana (E x E) having the tallest plants of 118 and 120 cm, respectively.
4.3.3.3 Across environments
The average days to heading across the no drought and the random drought environments was 77 days ranging from 70 to 92 days (Table 4.6). Days to heading of20% of the F3
populations were statistically shorter that the overall mean. The earliest populations with 70 days to heading were CT16323-CA-25-M x Vandana and NERICA 1 x Vandana. They had statistically significant shorter days to heading than their uncommon parents. The early class was dominated by crosses between E x E (eight populations) and E x EM (six populations).
The common parents were NERICA 2 appearing in six crosses and Vandana and CT16323- CA-25-M appearing in five crosses each. In addition, 59% of the selected early maturing class were between interspecific and Oryza sativa lines. The latest maturing crosses with days to heading of 90 and 91 days were between Oryza sativa lines. These were Luyin 46 x IR55423-01 (M x M), Luyin 46 x IR55423-01 (M x M) and IR55423-01 x I R74371-54-1-1 (M x EM) in that rank order. The common parents in the late class were IR55423-01 and Luyin 46. Number of productive tillers per plant ranged from 6 to 12 with a mean of eight tillers per plant. The late maturing population NERICA-L-25 x IR74371-54-1-1 showed the highest number of productive tillers per plant of 12 tillers. The average plant height across environments was 100 cm ranging from 92 to 109 cm. Among the selected populations, Duorado x Vandana and CT16323-CA-25-M x Vandana were the tallest. The population CT16323-CA-25-M x Vandana combined shorter days to heading with higher number of productive tillers per plant of 10 tillers and tall plants of 108 cm.
Table 4.4: Mean values of the earliest maturing 9 and latest maturing 11 F3 populations and their parents across no drought (Matuga, Mtwapa and Msabweni long rain season) environments
Genotypes DH† DA DM TNO PH
F3 populations with days to heading of 74 days and below
CT16323-CA-25-M x Vandana (E x E‡) 70 72 96 9 105
NERICA 1 x Vandana (E x E) 71 73 98 8 102
NERICA 1 x CT16323-CA-25-M (E x E) 72 74 99 7 96
NERICA 1 x CT16333(1)-CA-22-M (E x EM) 73 76 103 8 102
NERICA 2 x CT16323-CA-25-M (E x E) 73 77 105 7 97
NERICA 2 x Luyin 46 (E x M) 73 76 109 9 101
NERICA 1 x Dourado (E x E) 74 79 102 7 98
CT16333(1)-CA-22-M x CT16323-CA-25-M (EM x E) 74 76 104 7 95
NERICA 2 x Dourado (E x E) 74 77 106 8 100
F3 populations with days to heading of more than 80 days
Duorado x CT16333(1)-CA-22-M (E x EM) 80 83 109 9 105
Duorado x NERICA-L-25 (E x M 80 84 108 9 97
CT16333(1)-CA-22-M x NERICA-L-25 (EM x M) 80 83 113 7 107
IR55423-01 x Vandana (M x E) 82 86 111 10 101
NERICA-L-25 x IR74371-54-1-1 (M x EM) 82 83 114 12 98
NERICA-L-25 x IR55423-01 (M x M) 84 87 115 10 103
Luyin 46 x NERICA -L- 25 (M x M) 84 88 117 11 99
CT16333(1)-CA-22-M x IR55423-01 (EM x M) 89 92 120 8 97
IR55423-01 x IR74371-54-1-1 M x EM) 91 94 121 9 103
Luyin 46 x IR55423-01( M x M) 91 95 123 11 100
Luyin 46 x IR74371-54-1-1 (M x EM) 92 96 109 11 89
Parents
CT16323-CA-25-M 73 76 97 7 95
Vandana 73 74 98 10 96
NERICA 1 74 76 102 7 95
Duorado 74 77 99 8 108
NERICA 2 77 80 107 7 93
IR74371-54-1-1 82 84 109 10 93
CT16333(1)-CA-22-M 82 84 105 7 105
IR55423-01 88 91 117 11 95
NERICA -L- 25 92 94 118 12 103
Luyin 46 92 95 116 11 97
Mean Across 78 81 108 9 99
Min 92 96 123 12 107
Max 70 72 96 7 89
LSD (0.05) 3 3 2 2 8
Matuga Mean 79 83 110 9 93
Mtwapa mean 83 85 112 7 96
Msambweni long rain mean 72 75 101 101 108
† DH, Days to heading; DA, Days to anthesis; DM, Days to maturity; TNO, Number of productive tillers per plant; PH, Plant height
‡E, Early maturing; EM, Early to medium maturing; M, Medium maturing; LSD, least square difference
Table 4.5: Mean values of the earliest maturing 15 and latest maturing 5 F3 populations and their parents under random managed drought stress
Genotypes DH† DA DM TNO PH
F3 populations with days to heading of 71 days and below
Duorado x IR74371-54-1-1 (E‡ XEM) 66 68 102 9 100
CT16323-CA-25-M x IR55423-01(E x M) 67 71 102 10 106
CT16323-CA-25-M x IR74371-54-1-1( E x EM) 67 69 99 9 99
NERICA 1 x Vandana (E x E ) 69 71 96 8 101
CT16323-CA-25-M x Vandana (E x E ) 70 72 96 10 118
NERICA 1x NERICA 2(E x E ) 70 73 103 9 98
NERICA 2 x CT16333(1)-CA-22-M (E x EM) 70 74 104 7 97
NERICA 2 x Vandana (E x E ) 70 73 109 8 98
Duorado x Vandana (E x E ) 70 72 98 9 120
NERICA 1 x IR74371-54-1-1(E x EM) 71 73 102 9 105
NERICA 2 x IR55423-01(E x M) 71 73 103 10 98
NERICA 2 x IR74371-54-1-1(E x EM) 71 73 100 10 101
Luyin 46 x Vandana (M x E) 71 74 107 10 107
NERICA 2 x Luyin 46(E x M) 71 74 103 9 99
Vandana x IR74371-54-1-1(E x EM) 71 73 105 11 108
F3 populations with days to heading of more than 80 days
Luyin 46 x IR74371-54-1-1 (M x EM) 81 84 113 12 105
NERICA-L-25 x IR55423-01 (M x M) 81 87 119 10 84
NERICA-L-25 x Vandana (M x E) 84 87 116 9 111
IR55423-01 x IR74371-54-1-1 (M x EM) 87 89 123 9 97
Luyin 46 x IR55423-01 (M x M) 88 92 121 10 99
Parents
Duorado 71 73 98 8 119
Vandana 72 74 96 10 111
NERICA 1 75 78 99 7 94
CT16323-CA-25-M 77 80 102 8 95
NERICA 2 77 81 104 8 94
CT16333(1)-CA-22-M 80 83 113 5 103
IR74371-54-1-1 82 86 112 10 99
Luyin 46 87 92 116 10 106
IR55423-01 88 91 118 10 95
NERICA-L-25 91 96 123 12 82
Means 75 77 106 9 102
Max 88 92 123 12 120
Min 66 68 96 7 84
LSD (0.05) 6 6 5 2 10
† DH, Days to heading; DA, Days to anthesis; DM, Days to maturity; TNO, Number of productive tillers per plant; PH, Plant height
‡E, Early maturing; EM, Early to medium maturing; M, Medium maturing; LSD, Least square difference
Table 4.6: Mean values of the earliest maturing 17 and latest maturing 8 F3 populations and their parents across non stress and random managed stress environments
Genotypes DH† DA DM TNO PH
F3 populations with days to heading of 74 days and below
CT16323-CA-25-M x Vandana (E x E‡) 70 72 96 10 108
NERICA 1 x Vandana(E x E) 70 73 98 8 101
NERICA 1 x CT16323-CA-25-M (E x E) 72 74 98 7 94
NERICA 1 x CT16333(1)-CA-22-M (E x EM) 73 76 103 7 101
CT16323-CA-25-M x IR55423-01 (E x M) 73 76 107 8 98
NERICA 2 x CT16323-CA-25-M (E x E) 73 77 104 6 95
Duorado x IR74371-54-1-1(E x EM) 73 75 105 8 99
NERICA 1 x Duorado (E x E) 73 78 102 7 98
CT16333(1)-CA-22-M x CT16323-CA-25-M (EM x E) 73 76 103 7 95
NERICA 2 x Vandana (E x E) 74 76 106 8 98
NERICA 2 x IR74371-54-1-1(E x EM) 74 76 104 9 95
Duorado x Vandana (E x E) 74 76 103 9 108
CT16333(1)-CA-22-M x Luyin 46 (E M x E) 74 77 107 8 100
NERICA 2 x CT16333(1)-CA-22-M (E x EM) 74 77 107 7 99
Duorado x Luyin 46 (E x M) 74 76 104 9 101
NERICA 2 x Duorado (E x E) 74 77 105 7 99
NERICA 2 x IR55423-01 (E x M) 74 77 106 9 99
F3 populations with days to heading of more than 80 days
NERICA -L- 25 x IR74371-54-1-1 (M x EM) 80 82 114 12 102
IR55423-01 x Vandana 80 83 110 11 102
Luyin 46 x NERICA -L- 25 (M x M) 82 86 116 10 100
NERICA -L- 25 x IR55423-01 (M x M) 83 87 116 10 98
CT16333(1)-CA-22-M x IR55423-01 (EM x EM) 85 89 119 8 97
Luyin 46 x IR74371-54-1-1 (M x EM) 89 93 110 11 93
IR55423-01 x IR74371-54-1-1 (M x EM) 90 93 121 9 102
Luyin 46 x IR55423-01 (M x M) 91 94 122 11 100
Parents
Vandana 73 74 97 10 100
Duorado 74 76 99 8 111
CT16323-CA-25-M 74 77 98 7 95
NERICA 1 74 76 101 7 94
NERICA 2 77 80 106 7 93
CT16333(1)-CA-22-M 81 84 107 7 105
IR74371-54-1-1 82 84 110 10 94
IR55423-01 88 91 117 11 95
Luyin 46 91 94 116 11 99
NERICA -L- 25 92 95 119 12 98
Means 77 80 107 9 100
Max 91 94 122 12 109
Min 70 72 96 6 92
LSD (0.05) 3 3 2 1 7
† DH, Days to heading; DA, Days to anthesis; DM, Days to maturity; TNO, Number of productive tillers per plant; PH, Plant height
‡E, Early maturing; EM, Early to medium maturing; M, Medium maturing; LSD, Least square difference
4
47
36
7 7
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
Extra early (≤ 70) Early (71 -75) E arly -Medium (76 -80)
Medium (81 -85) Late > 85
% F3populations
Days to heading